Electrical circuit breaker



Nov 24, 1953 R. E. WARREN 2,660,642

ELECTRICAL CIRCUIT BREAKER Filed Aug. 2 1951 Inventor 1 Robert E. Warren,

Jag

His Attorney.

Patented Nov. 24, 1953 ELECTRICAL CIRCUIT BREAKER Robert E. Warren,

Marblehead, Mass., assignor to General Electric Company, a corporation of New York Application August 2, 1951, Serial N 0. 239,932

7 Claims.

My invention relates particularly to a construction for making and breaking a circuit by hand or by thermally actuated mechanism.

One object is to provide a simple and effective mechanism in which the circuit is automatically broken upon a predetermined rise in the ambient temperature.

Another object is to provide a circuit breaker capable of a great number of operations without failure.

Another object is to provide a circuit breaker of the quick-make-and-break type utilizing a compression spring for its main operating spring.

Fig. 1 is a side View and partial section showing one form of mechanism embodying my invention, the switching elements being shown in the closed circuit position.

Fig. 2 is a similar view showing the parts in the open circuit position.

Fig. 3 is a fragmentary plan view and section on the plane of the line 3-3 of Fig. 1.

Fig. 4 is a vertical sectional view of the housing taken generally on the plane of the line 44 of Fig. 1 and showing the mechanism including 7 a fragment of the bimetal member.

Fig. 5 is a side view and partial section showing the parts in the automatically tripped position.

The mechanism may be enclosed in a suitable housing such as the parts [0, It. The mechanism may be provided with suitable terminals such as H and I 2 and contacts i3 and I4, the contact 3 being connected to the terminal H and the contact l4 being connected to the terminal i 2 through the heater coil 15. The bimetallic strip i6 is anchored at I! and provided with a calibrating screw I 3 and a lateral holding on latching extension It" at its upper end.

The movable switch contact members 20, are carried by a slidable switch member 22 which is guided in grooves 23, 23 in the walls of the housing.

The movable contacts may be resiliently held in position by springs 24 carried by the sliding member 22.

The manual actuating mechanism includes the finger piece 25 which is hinged at 2'6. An L- shaped tripping member 21 has side pieces connected by a cross wall 27' and has a tip 29 on one of the side pieces which normally engages the lateral extension IE of the bimetal strip 16. A compression type throwing spring 30 is mounted on the rod 30'. The upper end of the rod 30' engages a pin 3! carried by the actuating lever 25 while its lower end is provided with a longitudinal slot 34 through which extends the bottom length 32' of the U-shaped link 32 whereby a pivotal and slidable connection is formed between the lower ends of the rod 3i! and the link 32. The lower end of the rod 39' and the spring extend through an opening 22 in the sliding member 22 with the spring abutting against the bottom 32' of the U-shaped link 32 and the upper end of the spring abutting against the stop 33 on rod 38'. I

The side arms of the link 32 extend upward through notches 35 in the sliding switch member 22 whereby the link is connected to the switch member, and the upper ends of the link 32 are hinged or pivoted at intermediate points 35, .35 on the upper arms of the tripping member 21. The spring 36 biases the link 32 downwardly so asto maintain the tip 29 of the tripping memher in yielding engagement with the extension it at the upper end of the bimetal strip [6.

To operate the switching mechanism manual- 1y to open the circuit from the position shown in Fig. 1, the actuating lever 25 is moved to the left. When the upper end of the rod 35' passes to the right of the center line of the plane containing the lower end of the throwing rod and the hinge axis 25, the spring throws the movable switch member with a toggle and snap action to the open circuit position. The link 32 serves as a switch contact operating arm or member. To close the circuit from the position of Fig. 2 to the position of Fig. 1, it is merely necessary to move the actuating finger piece 25 to the right and when the upper end of the throwing rod 35 passes to the left of the central plane containing the axis of the actuating member 25 and the plane of the lower end of the link member 32, the spring will throw the switch member 22 to the right and close the circuit.

When the temperature in the coil I 5 reaches a predetermined degree in response to a predetermined high current through the switch 2%, the heat will warp the upper end of the bimetal strip lfito the left from beneath the, tip 29 of the tripping member 27, thus allowing the spring 30 to draw the tripping member downwardly to the position shown in Fig. 5. The spring 30 moves the link member 32 downwardly and tilts the throwing rod 3!! to the position of Fig. 5. The movement of the throwing rod thus forces the sliding switch member 22 to move to the open circuit position opening the circuit and leaving the actuating lever 25 in the indicating midposition where the projections 38, 33 support the tripping member 21. The upper arms of the tripping member engage the projections 38, 38 and draw the lever 25 to the midposition of Fig. 5 in which the projections 38, 3B are seated respectively in the angles 38 on the inner edges at the junction of the two arms of each of the two side pieces of the tripping member.

If the handle 25 is held in the on position of Fig. 1 when tripping occurs, the contacts will still be moved to the open position. This is true because trip member 21 carries pivot 36 across the line of action of spring 30, causing spring 30 to reverse its bias on link 32 and move it to the open position as described above even though trip member 21 does not move fully to the position of Fig. 5.

To reset the mechanism after automatic tripping, the finger piece 25 is moved to the left from the mid-position of Fig. 5 and the projections 38, 38 on the actuating lever 25, engaging the lower arms of the tripping member 21, swings the tripping member to the right as shown in Fig. 2 thus bringing the parts to the open circuit position ready to be moved to reclose the circuit when desired.

it will thus be noted that when the mechanism is automatically tripped, the actuating finger piece 25 stands in the position shown in Fig. 5, thus indicating that the circuit has been opened automatically. In other words, there are three indicating positions of the actuating finger piece 25, first: as shown in Fig. 1 to indicate that the circuit is closed, a second: in Fig. 2 to indicate that the circuit has been opened manually, and a third: in Fig. 5 to indicate that the circuit has been opened automatically.

In moving from the position of Fig. .5 to that of Fig. 2 the tripping member 21 is turned clockwise and the link 32 drawn up so as to compress spring 30.

I claim:

1. A circuit breaker comprising a switch operating arm, a first pivot for one end of said arm, means supporting said first pivot for movement from one position to another, holding means engaging said supporting means for normally securing said supporting means with said first pivot in one of said positions, a manually operated member mounted on a second pivot adjacent said one position such that said first pivot moves away from said member in moving to its other position, compression spring means having one end connected to the movable end of said operating arm and its opposite end connected to said manually operated member thereby to bias said supporting means away from said manually operated member toward its other position and snap said operating arm from one position to another upon movement of said manually operated member to move said opposite end of said spring from one side to the other of said first pivot, switch means operated by said arm, and means responsive to the current in said switch means for operating said holding means to release said supporting means upon the occurrence of a predetermined high current for movement of said supporting means by said spring means to move said first pivot to its other position on the opposite side of said spring there by to snap said operating arm to an open circuit position.

2. A circuit breaker comprising a tripping member pivotally mounted at one end, holding means normally securing said tripping member in a predetermined position, a handle mounted on a pivot adjacent an outer edge of said tripping member and opposite an intermediate point of said tripping member, said handle having an operating portion extending from said handle and pivot toward said tripping member, an. operating arm having one end pivotally mounted on said tripping member at said intermediate point and extending away from the pivot of said handle, compression spring means having one end connected to said operating portion of said handle and its opposite end connected to the opposite end of said operating arm thereby to bias said tripping member in a direction away from the pivot of said handle and snap said operatingarm from one position to another upon movement of said handle to move said spring means from one side to the other of the pivot of said operating arm, switch means operated by said arm, means responsive to the current in said switch means for operating said holding means upon the occurrence of a predetermined high current so as to release said tripping member for movement by said spring means to move the pivot of said operating arm to the opposite side of the line of action of said spring means thereby to snap said operating arm to an open circuit position.

3. A circuit breaker comprising a tripping member pivotally mounted at one end, holding means normally securing said tripping member in a predetermined position, a handle mounted on a pivot adjacent an outer edge of said tripping member and opposite an intermediate point of said tripping member, said handle having an operating portion extending from said handle and pivot across said tripping member, an operating arm having one end pivotally mounted on said tripping member at said intermediate point and extending away from the pivot of said handle, compression spring means having one end connected to said operating portion of said handle and its opposite end connected to the op posite end of said operating arm thereby to bias said tripping member in a direction away from the pivot of said handle and snap said operating arm from one position to another upon movement of said handle to move said spring means from one side to the other of the pivot of said operating arm, switch means operated by said arm, means responsive to the current in said switch means for operating said holding means upon the occurrence of a predetermined high current so as to release said tripping member for movement by said spring means to move the pivot of said operating arm to the opposite side of the line of action of said spring means thereby to snap said operating arm to an open circuit position, and a projection on said operating portion of said handle engaging the inner edge of said tripping member when said handle is moved to an open circuit position thereby to reset said tripping member in said predetermined position.

4. A circuit breaker comprising a tripping member pivotally mounted at one end and provided with an intermediate seat on an inner edge, holding means normally securing said tripping member in a predetermined position, a handle mounted on a pivot adjacent the opposite outer edge of said tripping member and opposite an intermediate point of said tripping member, said handle having an operating portion extending across said tripping member, an operating arm having one end pivotally mounted on said tripping member at said inter-mediate point, compression spring means having one end connected to said operating portion of said handle and its opaeo eae posits end connected to the opposite end of said operating arm thereby to snap said operating arm from one position to another upon movement of said handle to move said spring means from one side to the other of the pivot of said operating arm, switch means operated by said arm, means responsive to the current in said switch means for operating said holding means upon the occurrence of a predetermined high current so as to release said tripping member for movement by said spring means to move the pivot of said operating arm to the opposite side of the line of action of said spring means thereby to snap said operating arm to an open circuit position, and a projection on said operating portion of said handle opposite the inner edge of said tripping member so as to be engaged and moved by said tripping member to a position in said seat whereby said handle is moved to an indicating position.

'5. A circuit breaker comprising a tripping member pivotally mounted on one end and formed by two arms joined at an angle forming a seat on its inner edge, holding means normally securing said tripping member in a predetermined position, a handle mounted on a pivot adjacent the outer edge of said tripping member and opposite an intermediate point of said tripping member, an operating arm having one end pivotally mounted on said tripping member at said intermediate point and extending away from the pivot of said handle, compression spring means having one end connected to said handle and its opposite end connected to the opposite end of said operating arm thereby to bias said tripping member in a direction away from the pivot of said handle and snap said operating arm from one position to another upon movement of said handle to move said spring from one side to the other of the pivot of said operating arm, switch means operated by said arm, means responsive to the current in said switch means for operating said holding means upon the occurrence of a predetermined high current so as to release said ,1

tripping member for movement by said spring to move the pivot of said operating arm across the line of action of said spring thereby to snap said operating arm to an open circuit position,

and a projection on said handle adjacent the inner edge of said tripping member so as to be engaged and moved by said tripping member to a position in said seat whereby said handle is moved to an intermediate indicating position,

said projection engaging said tripping member ping member, a first arm pivotally engaging said operating portion of said member, a second operating arm having one end pivotally mounted on said tripping member at said intermediate point, a pivotal and slidable connection between the opposite ends of said arms, a compression spring having one end secured to said first arm and its opposite end connected to said opposite end of said second arm thereby to snap said second arm from one position to another upon movement of said member to move the pivoted end of said first arm from one side to the other of the pivot of said second arm, switch means operated by said second arm, means responsive to the current in said switch means for operatsaid latch means upon the occurrence of a predetermined hi h current so as to release said tripping member for movement by said spring to move the pivot or" said second arm to the opposite side of the pivot of said first arm thereby to snap said second arm to an open circuit position.

7. A circuit breaker comprising a tripping member pivotally mounted on one end, a bimetallic strip mounted at one end and having its other end normally engaging the movable end of said tripping member so as to secure said tripping member in a predetermined position, a handle mounted on a pivot adjacent one edge of said tripping member and opposite an intermediate point of said tripping member, said handle having an operating portion extending across said tripping member to the opposite edge thereof, a first arm pivotally engaging said operating portion of said handle at a point adjacent said opposite edge of said tripping member, a second operating arm having one end pivotally mounted on said tripping member at said intermediate point, a pivotal and slidable connection between the opposite ends of said arms, a compression spring having one end secured to said first arm and its opposite end connected to said opposite end of said second arm thereby to snap said second arm from one position to another upon movement of said handle to move the pivoted end of said first arm from one side to the other of the pivot of said second arm, switch means operated by said second arm, means responsive to the current in said switch means for heating said bimetal strip upon the occurrence of a predetermined high current so as to cause its free end to move and release said tripping member for movement by said spring to move the pivot of said second arm to the opposite side of the pivot of said first arm thereby to snap said second arm to an open circuit position, and a projection on the operating end of said handle engaged by said tripping member for moving said handle to an indicating position.

ROBERT E. WARREN.

References Cited in the file of this patent UNITED STATES PATENTS 

